The present invention relates to a printer for printing characters on rolled paper stored in a casing, and more particularly to a printer having functions of detecting the presence or absence of rolled paper in a casing and of detecting an open or closed state of a door cover for making the rolled paper storable.
There is a related art printer generally called a rolled-paper printer that has a housing space in a casing and is used for printing characters on paper that is led out of a paper roll. As it is unnecessary to supplement paper to such a rolled-paper printer over a long period of time, the rolled-paper printer is suitable for use as a printer together with a cash register or the like. The rolled-paper printer is provided with a door cover for opening or closing a part of the housing space so that an operator can put rolled paper in the housing space by opening the door cover.
In the related art rolled-paper printer is equipped with several condition sensors like common printers in order to inform an operator of internal conditions thereof. These sensors include a cover state sensor for detecting the state of the door cover, that is, for detecting whether the cover is opened or closed, and a paper detection sensor for detecting the presence or absence of the rolled paper in the housing space.
The cover state sensor is formed with, for example, an optical sensor and a micro-switch, wherein the optical sensor is disposed near a free end of a door cover. The cover state sensor is used for detecting the change in quantity of received light, and for detecting the on-off states of a switch resulting from the movement of a specific portion (e.g., an extended area of the frame) of the door cover at the time the cover is opened or closed. The paper detection sensor is formed with, for example, an optical sensor and a micro-switch, wherein the optical sensor is disposed in a housing space. The paper detection sensor is used for detecting the change in quantity of received light, and for detecting the on-off states of the switch resulting from the presence or absence of the rolled paper.
On the other hand, in order to facilitate installing a rolled paper in the housing space, another rolled-paper printer is so arranged that a paper drawn out from the rolled paper is released from a paper path when the door cover is opened. For example, a print head and a platen are moved away from one another, and a pair of feed rollers are moved away from each other when the door cover is opened. With this arrangement of the printer, the paper may be moved away from a paper detection sensor disposed in the paper path as the door cover opens.
Consequently, when the paper detection sensor detects the movement of the paper as the door cover opens before the cover state sensor detects the movement of the door cover, an error in detection may occur and the problem is that the operator receives false information. Namely, the printer may inform to the operator or user xe2x80x9cpaper endxe2x80x9d instead of xe2x80x9ccover openxe2x80x9d, while the remaining amount of the paper is enough for printing.
It may be configured that the printing is halted or forbidden without identifying the kind of error (paper end or cover open) because troubles would occur if the printing is continued under any of the error conditions. However, in a case where a printer is loaded in a POS (point-of-sales) cash register or the like, it is necessary to notify which error is occurred to direct a next operation to an operator.
It is therefore an object of the present invention to provide a printer so arranged as to ensure that a sensor for detecting the state of a door cover outputs its detected result before a sensor for detecting the presence or absence of rolled paper outputs its detected result.
In order to achieve the above object, according to the present invention, there is provided a printer comprising:
holder, which accommodates paper therein;
a cover, which is movable between a first position for covering the paper accommodated in the holder and a second position for opening the holder such that an operator is able to access the accommodated paper;
a print mechanism, which transports the paper and prints information thereon;
a print controller, which controls the print mechanism to perform printing process;
a cover state detector, which outputs a first detection signal when the cover is moved from the first position to the second position;
a paper detector, which outputs a second detection signal when the paper has run out; and
a delay generator, which delays the transmission of the second detection signal to the print controller relative to the first detection signal.
With the arrangement above, it is ensured that when the cover is placed in the second position (opened), the first detection signal outputted from the cover state detector is obtained before the second detection signal outputted from the paper detector. Thus, an error in detection is presented from occurring when the cover is opened.
According to the invention, there is also provided a printer comprising:
a holder, which accommodates paper therein;
a cover, which is movable between a first position for covering the paper accommodated in the holder and a second position for opening the holder such that an operator is able to access the accommodated paper;
a print mechanism, which transports the paper and prints information thereon;
a print controller, which controls the print mechanism to perform printing process;
a cover state detector, which outputs a first detection signal when the cover is moved from the first position to the second position, the cover state detector including a first lever, which moves in cooperation with the movement of the cover, and a first detector that detects the movement of the first lever;
a paper detector, which outputs a second detection signal when the paper has run out, the paper detector including a second lever, which moves in cooperation with the movement of the cover and moves when the paper accommodated in the holder runs out, and a second detector that detects the movement of the second lever; and
a support member, which supports the cover state detector and the paper detector such that the movement of the first lever is detected by the first detector prior to when the movement of the second lever is detected by the second detector.
Here, it is preferable that the printer further comprises, a frame that supports the holder, a print head disposed on one of the cover or the frame, and a platen disposed on the other one of the cover or the frame. The platen is opposed to the print head so as to perform printing on the paper guided therebetween, while the cover is placed in the first position.
Preferably, the first and second levers are arranged to pivot around an axis that is perpendicular to a direction in which the paper is transported.
Preferably, the printer further comprises: a guide plate, which guides the paper toward the print mechanism; and an urging member that urges each of the first and second levers toward the guide plate.
Here, it is preferable that the guide plate is formed with a cutout portion into which the second lever enters, when the paper accommodated in the holder runs out. Also, the second detector detects the movement of the second lever when the second lever enters the cutout portion.
Preferably, the first and second levers are pivotably supported by the support member. Also, the first detector includes a first button switch onto which the first lever abuts Further, the second detector includes a second button switch onto which the second lever abuts.
Preferably, the printer further comprises a notifier, which notifies that the cover is opened, when the movement of the first lever is detected by the first detector, and which notifies that the paper accommodated in the holder has run out, when the movement of the second lever is detected by the second detector.
According to the invention, there is also provided a printer comprising:
a holder, which accommodates paper therein;
a cover, which is movable between a first position for covering the paper accommodated in the holder and a second position for opening the holder such that an operator is able to access the accommodated paper;
a print mechanism, which transports the paper and prints information thereon;
a print controller, which controls the print mechanism to perform printing;
a cover state detector, which outputs a first detection signal when the cover is moved from the first position to the second position;
a paper detector, which outputs a second detection signal when the paper has run out; and
a delay circuit that delays the transmission of the second detection signal to the print controller relative to the first detection signal.
Here, it is preferable that the printer further comprises: a frame that supports the holder; a print head disposed on one of the cover or the frame, and; a platen disposed on the other one of the cover or the frame, wherein the platen is opposed to the print head so as to perform printing on the paper guided therebetween, while the cover is placed in the first position.
According to the invention, there is also provided a printer comprising:
a holder, which accommodates paper therein;
a cover, which is movable between a first position for covering the paper accommodated in the holder and a second position for opening the holder such that an operator is able to access the accommodated paper;
a print mechanism, which transports the paper and prints information thereon;
a cover state detector, which outputs a first detection signal when the cover is moved from the first position to the second position;
a paper detector, which outputs a second detection signal when the paper has run out; and
a controller for controlling the print mechanism to perform printing process,
wherein the controller executes a first interruption process prior to the printing process, when receiving the first detection signal within a predetermined time period, and executes a second interruption process that is different from the first interruption process, when receiving no first detection signal within the predetermined time period.
Here, it is preferable that the printer further comprises a timer, which counts the predetermined time period. The controller executes the first interruption process, when receiving the first detection signal prior to the second detection signal. The timer starts to count the predetermined time period, when receiving the second detection signal prior to the first detection signal.
Preferably, the controller halts or forbids printing process, during each of the first and second interruption processes.
Further, preferably, the printer comprises a notifier, which notifies that the cover is opened, when the first interruption process is executed.
Moreover, preferably, the printer further comprises a notifier, which notifies that the paper accommodated in the holder has run out, when the second interruption process is executed.
According to the present invention, there is also provided an error process method, used for the above printer provided with a holder, which accommodates paper therein; a cover, which is movable between a first position for covering the paper accommodated in the holder and a second position for opening the holder such that an operator is able to access the accommodated paper; a print mechanism, which transports the paper and prints information thereon; a cover state detector, which outputs a first detection signal when the cover is moved from the first position to the second position and; a paper detector, which outputs a second detection signal when the paper has run out; the error process method comprising the steps of:
counting a predetermined time period, when receiving the second detection signal;
executing a first interruption process prior to a printing process, when receiving the first detection signal the predetermined time period; and
executing a second interruption process, which is different from the first interruption process, when receiving no first detection signal within the predetermined time period.
Preferably, the first interruption process is executed when receiving the first detection signal prior to the second detection signal. And the counting step is established when receiving the second detection signal prior to the first detection signal.
Also, preferably, each of the first and second interruption processes includes a step of halting or forbidding the printing.
Further, preferably, the first interruption process includes at least one of the steps of: notifying a cover open error to a host connected to the printer; and notifying a cover open error to the operator through a notifier provided with the printer.
Still further, preferably, the second interruption process includes at least one of the steps of., notifying a paper end error to a host connected to the printer; and notifying a paper end error to the operator through a notifier provided with the printer.
Moreover, preferably, the predetermined time period is so determined as to be smaller than a value L/v, where L is a distance between a printing position of the print mechanism and a detecting position of the paper detector, and v is a transporting velocity of the paper.